I’ve an 1985 Ford Bronco 2. Yeah I know. Why did you buy that piece of garbage. Well I needed a second vehicle. It was cheap. Anyway I’ve done some engine work on older vehicles pre 80’s but nothing on something like this. Computer + Carb = BAD! I am having hesitation problems and sometimes she won’t keep running at idle and she dies on me at stops frequently and somtimes when I push the clutch in! I’m thinking vacuum leak here. Any Ideas???
Kind of hard to believe a 24 year old vehicle might need a little work, huh?
A carbed vehicle dying at idle usually points to a vacuum leak, sticking EGR valve, ignition timing severely off, or an improperly adjusted carburetor.
The problem is not the vehicle.
There is likely a mixture control solenoid on the carburator. Remove it and several ports will be revealed. Start the engine and plug the ports, testing for an improvement in idle. When you find the one that improves the idle, plug it with aluminum foil pressed tightly into the port and replace the solenoid. Then, remove the limiters from the air/fuel adjusters and turn them out in 1/4 turn increments until it seems to run best. Then, set the timing as high as possible without detonation under load or hitting back on the starter. Finally, reduce the idle speed as needed, approx 850rpm.
Is your state testing 1985 vehicles for emissions? Adjusting a carb for best idle could cause your CO to be to high.Maybe your cat will keep it down.A pre-test sniff could keep you from a inital failure. Here in AZ they are testing 85’s our cut-off is 65.
If my assumption is correct, the truck would not pass any emissions test as it was and neither would it pass afterward, but it would be quite improved. The mid-80s carburators were a dismal failure. Diagnosis and proper repair today is not economical. As a trash hauler/back-up vehicle a truck such as that might be patched up and kept running many more years, though.
Ford wasn’t the only manufacturer of this era that came out with the feed-back carb management system. GM had this and was just as troublesome, and Chrylser had it’s Lean-Burn system which was a hoot.
On these systems you first check the basics that could cause the problem. After this, then you need a manual that explains how these feed-back systems operate, and how to troubleshoot them if that’s the problem. And if it is the problem, don’t be surprised if the carb assembly requires replacement.
It wasn’t just GM, Ford, and Chrysler that had problems with emission controlled carburetors and the assortment of thermovalves, switches, etc.
Nissan, Honda, Subaru, etc also had a myriad of problems. While others were cursing the Big Three I was cursing the same problems on these makes, with Subaru being the worst offender of all.
With Honda, we were modifying carbs before the car was even sold off the lot to the original owner.
Sounds like it’s ready for a trip to the dumpster.
One of the many 'TWEEN vehicle years. Analog technologies and carburators were trying to get superceded by computer tech which was still in it’s infancy. Try as they may, most of the ideas that looked good on paper just didn’t pan out, as you are finding and the other posters have mentioned. It will not get better for this truck.
One thing more. Check the ignition pickup if you have vacuum advance. Look for frayed wires at the pickup, especially with the manual transmission. Every time you shift, the pickup moves.
Who managed to make so many mistakes in one vehicle? Ford.
You have got to be kidding? You should have expected problems like these.
Computer + Carb = BAD!
True but Ford is not the only culprit
Replace the carb with an Autolite 2V from any '68-'79 Ford product.
ALL cars built '81-'86 are POS…If you must endure emissions testing, forget it…
If the problem isn’t the vehicle mabey you’ll help me push.
Don’t get me wrong guys. I like my 2004 Heretige F150 pickup. But this pos wasn’t thought out very well. And I think some more testing would have helped. And your right about Ford not being the only culprit. I’m just really frustrated by this vehicle because I’m the sucker who bought it. Thanks.
Thanks for all the great ideas. I’ll get to work on some of these and see what I come up with. Thanks a MILLION.
I don’t place the blame for 70s/80s era carburetor and emissions problems on the car makers. I place it on the Federal government.
The public demands clean air and the Feds mandate it.
The car makers were doing the best they could at the time to try and control mixture and emissions throughout the RPM and load range and it’s near impossible to have perfection like this on a carbureted vehicle.
It’s easy to look at modern cars with the latest computer controlled FI system and Monday morning quarterback the old systems but they did the best they could with what they had to work with.
Even the 60s/70s era fuel injection systems were thought of as high tech back then but are pretty crude when comparing them now. The old VW systems with the extra sets of contact points in the distributor below the breaker point plate to trigger the injectors for instance. Trick stuff then and near Neanderthal in retrospect.
I’ve seen some of the Subaru carburetors of this era…good God, there are so many ports, hoses, and wires I don’t know how you’d keep it all straight. Thank God for EFI.
GM was having MAJOR problems with their carbs of that era too. I had to rebuild my 84 carb with less then 60k miles. When I went to buy the rebuild kit…there were 14 different kits for that vehicle. A total of 20 different carbs were made for that vehicle…And that’s just the 2SE model. A bunch more were made for the E2SE model carb.